Bone anchors for attaching suture, bone and/or soft tissue to bone are well known in the art. See, for example, U.S Pat Nos. 4,898,156; 5,046,513; 5,192,303; 4,899,743; 4,968,315; 4,946,468; 5,002,550; 5,207,679; 5,217,486; 5,356,413; 5,358,511; and 5,372,599; and U.S. patent applications Ser. Nos. 08/075,168; 08/197,927; and 08/098,599.
Installation tools for deploying such bone anchors in bone are also well known in the art. See, for example, the foregoing U.S. patents and patent applications.
Complete details of the construction and operation of the foregoing exemplary bone anchors and bone anchor installation tools are provided in the above-identified patents and patent applications, which patents and patent applications are hereby incorporated herein by reference.
While the bone anchor installation tools disclosed in the foregoing U.S. patents and patent applications have proven more than satisfactory for most applications, it has been noted that certain problems can occur when using these installation tools in special situations.
More particularly, with some of the foregoing installation tools (e.g. the installation tools disclosed in U.S. Pat. Nos. 4,898,156; 5,046,513; 5,192,303; and 4,899,743), the portion of the tool which carries the anchor (i) is wider than the body of the anchor itself, and (ii) must be positioned within the bone during anchor deployment. As a result of this construction, the bone hole must be formed larger than the body of the anchor in order to permit anchor deployment. This can be a disadvantage in certain situations where it may be necessary to form the smallest possible hole in the bone.
With others of the foregoing installation tools (e.g. the installation tools disclosed in U.S. Pat. No. 5,217,486 and U.S. patent application Ser. No. 08/098,599), the portion of the tool which carries the anchor does not need to be received by the bone during anchor deployment. Instead, only a relatively thin drive pin enters the bone during anchor deployment. The drive pin is formed so that it has a diameter less than the diameter of the anchor body. As a result of this construction, the bone hole can be formed so that it has substantially the same width as the anchor body. However, it has also been found that where the installation tool is being used to set extremely small bone anchors, the drive pin must be so thin that it may bend or otherwise deform in certain circumstances. When this occurs, it may affect anchor deployment and/or render the installation tool unusable for subsequent anchor deployments.
In addition to the foregoing, it has also been found that where the installation tools are being used in conjunction with anchors adapted to attach suture to bone, it can be very helpful to provide suture management means for controlling the disposition of the one or more free suture ends. In this respect it is noted that with some of the foregoing installation tools (e.g. the installation tools disclosed in U.S. Pat. Nos. 4,946,468 and 5,002,550), such suture management means are provided. However, while such suture management means work well enough for most applications, it has been found that alternative suture management means could be helpful in some situations.